title: Label-free detection of cupric ions and histidine-tagged proteins using single poly(pyrrole)-NTA chelator conducting polymer nanotube chemiresistive sensor.
abstract: Novel chemical and biological sensors based on a single poly(pyrrole)-NTA chelator nanotube for sensitive, selective, rapid and real-time detection of histidine-tagged protein and cupric ions are reported. NTA groups on the nanotube surface provided a simple mechanism for metal ion sensing via the high-affinity interaction between NTA and the subsequent detection of histidine-tagged protein through the coordination with metal chelated nanotube. Poly(pyrrole)-NTA chelator nanotubes of 190 nm outside diameter, 35 nm wall thickness and 30 microm long were synthesized by electrochemical polymerization of pyrrole-NTA inside a 200 nm diameter alumina template and assembled as a chemoresistive device by bottom-up contact geometry on a pair of parallel gold electrodes with a gap distance of 3 microm. The chemoresistive sensors based on single poly(pyrrole)-NTA chelator nanotube exhibited detection as low as one-hundredth attomolar (0.6 ppt) cupric ions and 1 ng/ml of penta-histidine tagged syntaxin protein.
authors.affiliation: Department of Chemical and Environmental Engineering and Center for Nanoscale Science and Engineering, University of California-Riverside, Riverside, CA 92521, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Aravinda
authors.forename: Serge
authors.initials: S
authors.lastname: Cosnier
authors.forename: Wilfred
authors.initials: W
authors.lastname: Chen
authors.forename: Nosang V
authors.initials: NV
authors.lastname: Myung
authors.forename: Ashok
authors.initials: A
authors.lastname: Mulchandani
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002614:Chelating Agents / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004553:Electric Conductivity; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006639:Histidine / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*; D040081:Protein Array Analysis / Q000295:instrumentation* / Q000379:methods; D011758:Pyrroles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods
chemical_list: D002614:Chelating Agents; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006639:Histidine; D003300:Copper